Method of forming polymers on fibrous substrates through high velocity impingement with solutions containing unsaturated monomers and chemical catalysts



Dec. 13, 1966 G. MACHELL ETAL METHOD OF FORMING POLYMERS ON FIBROUSSUBSTRATES THROUGH HIGH VELOCITY IMPINGEMENT WITH SOLUTIONS CONTAININGUNSATURATED MONOMERS AND CHEMICAL CATALYSTS Filed Dec. 10, 1962INVENTORQ REV/LLE lMC/IELL ATTORNEY x THOM S United States Patent .0

METHOD OF FORMING P DLYMERS ON FIBROUS SUBSTRATES THROUGH HIGH VELOCITYIM- PIN-GEMENT WITH SOLUTIONS CONTAINING UNSATURATEI) MQNOMERS ANDCHEMICAL CATALYSTS Greville Machell and Manuel A. Thomas, Spartanhurg,

S.C., assignors to Deering Milliken Research Corporation, Spartanhurg,S.C., a corporation of Delaware Filed Dec. 10, 1962, Ser. No. 243,671 6Claims. (Cl. 8116) This invention relates to a novel process formodifying the characteristics of keratin fibers with compoundscontaining the group more particularly to a process for modifying woolfibers.

Compounds containing the group have been used to treat fabricscontaining wool fibers in the past, generally to impart increasedresistance to shrinking in aqueous media. Although the desiredshrinkproofing has been accomplished by these techniques, the aestheticproperties of the fabric have been diminished to the point that suchfabrics have not been acceptable commercially. The same ditficultyarises when such compounds are applied to wool fabrics for otherpurposes, e.g., to modify the dyeing characteristics thereof. Thisdiificulty has been partially overcome by conducting the reaction onloose fibers in accordance with the inventions described in copendingand coassigned US. patent application, Serial Number 242,6l0, filedDecember 6, 1962, and preparing a fabric from the treated fibers.

In attempting to treat loose fibers (i.e., fibers not in the form ofyarn or fabric), it was soon realized that some of the problemsassociated with treatment of fabric were still present. Moreparticularly, surface deposits of polymer, i.e., polymer which had notreacted with the fibers were still being formed, so that the handle ofthe fibers, though improved, was still not entirely satisfactory formany end uses.

In addition, it was found to be diflicult to treat loose fibers bytechniques suitable for treating fabrics without extensive modificationof apparatus normally used for modifying fabrics with compoundscontaining the group. For example, wool top can be quite readily pulledapart and, consequently, its not amenable to processes suitable fortreating fabrics.

Prior processes for modifying fabrics with compounds containing theCHz=(- group were found to present at least two basic ditficulties, inaddition to the heretofore insurmountable problem of boardy, coarsehandle. Firstly, it was discovered that the monomer available forreaction in the solutions utilized was being inefficiently converted toreacted material. Secondly, and more importantly, it was discovered thatin many instances, substantial amounts of the compound which wasconverted to reacted material were not permanently attached to thefibers, i.e., the reacted material could be readily stripped from thefibers by a solvent for the material. Since one of the reasons for usinga compound of the formula to treat wool fibers is to effect a reactionbetween the fibers and the compound, or at least to induce such arelationship that the reacted material could not be stripped readilyfrom the fibers, this discovery was most disturbing.

While difficulties presented by treating fabrics could be solved, atleast partially, by treating loose fibers and processing them intofabrics, additional improvement can be made by modifying radically theprocesses utilized in treating the fibers.

It is an object of this invention to modify the characteristics ofkeratin fibers in a process characterized by highly efficient conversionof the group-containing compounds to reacted material.

Another object of this invention is to increase substantially theproportion of said compound which reacts with the keratin fibers tototal reacted material.

Yet another object of this invention is to provide such a processwherein said compounds are applied uniformly to the keratin fibers beingtreated.

These and other objects are accomplished in accordance with thisinvention by repeatedly forcing through a mass of loose keratin fibers asolution of a compound containing the group in the presence of thedesired catalyst system. Preferably, the solution is repeatedly forcedback and forth through the mass of fibers at a sufficiently rapid ratethat the supply of monomer at the surfaces of the fibers is constantlybeing replenished in an amount considerably in excess of that which, atleast initially, the fibers can have exhausted thereon. This procedureis continued until the monomer in the solution is substantiallyexhausted onto and into the fibers.

Despite the more rapid and more complete conversion of the availablemonomer to reacted material, the reacted material, quite unexpectedly,is nearly completely-unextractable with a solvent for the polymeric formof the compound. One might reasonably expect that a compound beingabsorbed by a fiber more rapidly and in greater abundance would tend toreact not only with the fibers but also with itself to a greater extent.Keratin fibers treated in accordance with this invention, however, arecharacterized by far less extractable reacted material than fiberstreated by prior art immersion techniques. Furthermore, compoundscontaining the groups are reacted with the mass of fibers more uniformlythan in the prior art processes. If, however, it is desired to utilizethe process of this invention to place reacted material which isionically bound within the fibers, and hence extractable to a greaterdegree, many advantages will accrue even in this type process.

Generally, it is believed that in the presence of a suitable catalystsystem, compounds containing the group react with keratin fibers toproduce polymeric compounds permanently chemically attached, or grafted,to the wool fibers so as to be unextractable with a solvent for thepolymeric form of the. monomer or low polymer utilized. Under these sameconditions, in some instances, some of the monomer or low polymer canreact with itself rather than with the wool fibers to produce ahomopolymer which can be readily extracted from the wool fibers.

the fiber mass per minute.

This latter condition is a great deal less prevalent, if not in facteliminated, by the process of this invention.

It is realized, of course, that some homopolymer may form Within thefibers being treated by the process of this invention and that thismaterial, though homopolymeric in nature and not reacted with thefibers, would not be readily extractable. At any rate, even though thiscondition may existand it is not known in fact that it does the factstill remains that less reacted material can be removed from wool fiberstreated in accordance with this invention than from fibers treated inaccordance with immersion techniques using the same monomer or lowpolymer system.

There is no readily apparent explanation for the improvements providedby this invention and none will be attempted here. It is known, however,that when the monomer system is forced, preferably back and forth,through the mass of fibers in accordance with this invention, little orno reacted material is removed during extraction techniques.

In general, excellent improvement is provided when the monomer is forcedthrough the mass of fibers, most preferably in the form of loose fibersas set forth above, at a rate in excess of about 5 pounds ofmonomer/pound of fibers/minute. Generally, this amount constitutes anexcess of at least about 1000 times that amount of monomer which cantheoretically exhaust initially on Under these conditions, the monomerexhausts onto and into the fibers themselves at an average rate inexcess of about 0.005 pound of monomer/ pound of fibers/ minute.

These conditions are most readily obtained in equipment which isnormally used in the package dyeing of yarn. Generally, however, theflow rate of the system through this apparatus must be adjusted to alevel whereby the monomer or low polymer system is forced through themass of fibers at a sufficiently rapid rate that the supply of monomerat the surface of the fiber is constantly being replenished in an amountconsiderably in excess of that which, at least initially, the fiber canhave exhausted thereon. In most package dyeing machines, this conditionis readily obtainable. If sufficient flow is not provided by theselected equipment, this difficulty can generally be overcome byselecting a higher capacity pump or by decreasing the load of woolfibers in the equipment. These latter expedients are suggested should alarge amount of extractable reacted material be noticed after a few runsusing the equipment.

Wool fibers are generally treated with an aqueous solution of thedesired monomer or low polymer in the presence of a catalyst systemcapable of inducing polymerization thereof. The catalyst system mostgenerally used is a redox catalyst system composed of a reducing agentand an oxidizing agent. The prior art teaches that wool fibers should beimpregnated with one of these catalyst components and then contactedwith the monomer and the other catalyst component, in the belief thatthe monomer will polymerize in a solution containing both catalystcomponents. This in fact does occur in many of the prior art immersionbaths. For some reason, again unexplainable, the expected polymerizationdoes not occur when a single system containing the desired monomer andall catalyst components is applied to wool fibers under the conditionsof flow utilized in accordance with this invention. This characteristicof the invention, therefore, constitutes a distinct advantage of thisinvention over the prior art immersion techniques in that far superiorcontrol of the process is possible when all components can be added froma single bath.

The reducing agent and/or the oxidizing agent, however, may be appliedto the fibers prior to the application of the monomer, or vice versa.

The preferred redox catalyst system is composed of a reducing agent andan oxidizing agent initiator, the interaction of which provides freeradicals which cause polymerization of the monomeric or low polymericmaterial with the keratin substrate.

The reducing agent may be an iron compound, such as the ferrous saltsincluding the sulfates, acetates, phosphates, ethylenediaminetetra-acetates and the like; metallic formaledhyde sulfoxylates, such aszinc formaldehyde sulfoxylate; alkali-metal sulfoxylates, such as sodiumformaldehyde sulfoxylate; alkali-metal sulfites, such as sodium andpotassium bisulfite, sulfite, metabisnlfite or hydrosulfite; mercaptanacids, such as thioglycollic acid and its water-soluble salts, such assodium, potassium or ammonium thioglycollate; mercaptans, such ashydrogen sulfide and sodium or potassium hydrosulfide; valkylmercaptans, such as butyl or ethyl mercaptans and mercaptan glycols,such as beta-mercaptoethanol; alkanolamine sulfites, such asmonoethanolamine sulfite and monoisopropanolamine sulfite; manganous andchromous salts, ammonium bisulfite, sodium sulfide, sodium hydrosulfide,cysteine hydrochloride, sodium hypophosphite, sodium thiosulfate, sodiumdicyanate, titanous chloride, sulfur dioxide, sulfurous acid and thelike, as well as mixtures of these reducing agents. In addition, a saltof hydrozine may be used as the reducing agent, the acid moiety of thesalt being derived from any acid such as hydrochloric, hydrobromic,sulfuric, sulfurous, phosphoric, benzoic, acetic and the like.

Suitable oxidizing agents initiators for use in the redox catalystsystem include inorganic peroxides, e.g., hydrogen peroxide, bariumperoxide, magnesium peroxide, etc., and the various organic peroxycatalysts, illustrative examples of which are the dialkyl peroxides,e.g., diethyl peroxide, dipropyl peroxide, dilauryl peroxide, dioleylperoxide, distearyl peroxide, di-(tert.-butyl) peroxide anddi-(tert.-amyl) peroxide, such peroxides often being designated asethyl, propyl, lauryl, oleyl, stearyl, tert.-butyl tert.-amyl peroxides;the alkyl hydrogen peroxides, e.g., tert.-butyl hydrogen peroxide(tert.-butyl hydroperoxide), etc.; symmetrical diacyl peroxides, forinstance peroxides which commonly are known under such names as acetylperoxide, propionyl peroxide, lauroyl peroxide, stearoyl peroxide,malonyl peroxide, succinyl peroxide, phthaloyl peroxide, benzoylperoxide, etc.; fatty oil acid peroxides, e.g., coconut oil acidperoxides, etc.; unsymmetrical or mixed diacyl peroxides, e.g., acetylbenzoyl peroxide, propionyl benzoyl peroxide, etc.; terpene oxides,e.g., ascaridole, etc.; and salts of inorganic peracids, e.g., ammoniumpersulfate, potassium persulfate, sodium percarbonate, potassiumpercarbonate, sodium perborate, potassium perborate, sodiumperphosphate, potassium perphosphate, etc.

Other examples of organic peroxide initiators that can be employed arethe following: tetralin hydroperoxide, tert.-butyl diperphthalate,cumene hydroperoxide, tert.- butyl perbenzoate, 2,4-dichlorobenzoylperoxide, urea peroxide, caprylyl peroxide, p-chlorobenzoyl peroxide,2,2-bis(tert.-butyl peroxy) butane, hydroxyheptyl peroxide, diperoxideof benzaldehyde.

The above oxidizing agents, particularly the salts of inorganicperacids, may be utilized alone to initiate the graft polymerizationprocess, although faster reactions at lower temperatures may beconducted when the oxidizing agent is combined with a reducing agent toform a redox catalyst system. Also, ferric salts can be used asoxidizing agents and form a redox catalyst system with hydrogenperoxide, in which case the peroxide functions as a reducing agent.

Other suitable catalysts or initiators for the polymerization processinclude azo catalysts, such as azobisisobutyronitrile, as well asirradiation under the influence of high energy fields, including thevarious actinic radiations, such as ultra-violet, X-ray, and gammaradiations, as well as radiation from radioactive materials, such ascobalt-60.

The processes of this invention may be utilized to apply to keratinfibers any compound which will react with the fibers and polymerizethereon. The most satisfactory compounds are characterized by the groupand include both the monomeric and low polymeric (readily polymerizable)forms of these compounds. Included within this class of compounds areN-dialkyl acrylamides, e.g., N,N'-dimethyl, -diethy1, -dipropyl,-dibutyl, -diamyl, -dihexyl, -dioctyl, etc., acrylamides,N-(panisyl)methacrylamide, N (p chl0ropheny1)methacrylamide, N-phenylmethacrylamide, N-ethylmethylrnethacrylamide, N-methylmethacrylamide,N-(p-tolyDmethacrylamide and the like; the acrylic, alpha-alkyl acrylicand alpha-haloacrylic esters of saturated monohydric alcohols, forinstance saturated aliphatic monohydric a1- cohols, e.g., the methyl,ethyl, propyl, isopropyl, butyl, isobutyl, amyl, etc., esters ofacrylic, methacrylic, ethacrylic, propacrylic, chloroacrylic,bromoacrylic, aconitic, itaconic, maleic, crotonic, fumaric etc., acids;these latter acids and anhydries thereof; the phenyl, benzyl,phenylethyl, etc., esters of the aforementioned acids; vinyl aromaticcompounds, e.g., styrene; methylstyrenes, such as 0-, m-,p-methylstyrene; dirnethylstyrenes, such as 2,5-dimethylstyrene;halogenated styrenes, such as -bromostyrene, p-bromostyrene,p-iodostyrene, pentachlorostyrene, dichlorostyrene,a,,8,,8-trifiuorostyrene, 2,5 bis(trifluoromethyl)styrene,3-trifluoromethylstyrene and the like; the various cyanostyrenes; thevarious methoxysty-renes, such as p-methoxystyrene, vinyl naphthalcnes,such as 4-chlorol-vinylnaphthalene, 6-chloro 2 vinylnaphthalene, etc.;vinyl and vinylidene halides, e.g., vinyl and vinylidene chlorides,bromides, etc.; alkyl vinyl ketones, e.g., methyl vinyl ketone, ethylvinyl ketone, methyl isopropenyl ketone, etc.; itaconic and maleicdiesters containing a single group e.g., the dimethyl, diethyl,di-B-chloroethyl, diethylchloro, dipropyl, disopropyl, dibutyl and othersaturated aliphatic monohydric alcohol diesters of itaconic and maleicacid, diphenyl itaconate and maleate, dibenzyl itaconate and maleate,di-(phenylethyl) itaconate and maleate, etc.; vinyl allyl and metallylesters of saturated aliphatic monocarboxylic acids, e.g., vinyl, allyland metallyl acetates, vinyl, allyl and metallyl propionates, vinyl,allyl and methallyl valerates, etc.; vinyl thiophene; vinyl pyridine,vinyl pyrrole; nitriles containing a single 7 OH2=C|3 group, e.g.,acrylonitrile, methacrylonitrile, etc.

Additional suitable ethylincally unsaturated compounds include:

l-acetoxy-l,3-butadieneacrolein; allyltriethoxysilane;N-benzylidene-4-methacryloxyaniline; bis (trimethylsiloxy)vinylmethylsilane; S-bromovinyl ethyl ether; 1,3-butadiene;Z-butenyltriethoxysilane;

n-butyl cinnamate;

n-butyl crotonate;

N-butyl crotonate;

N-butyl maleirnide;

n-butyl vinyl ether;

tert-butyl vinyl ether, 11 butyl vinylsulfonate; 2-chloroallyl acetate;

2-chloroallyl alcohol; u-chlorovinyltriethoxysilane; citraconicanhydn'de; crotonaldehyde, crotonic acid; 1-cyano-l,3-butadiene;

diallyl phthalate; 4,6-diamino-Z-vinyl-s-triazine;2,3-dichloro-1,3-butadiene;

diethoxyethylvinylsilane;

diethoxymethylvinylsilane;

diethoxyphenylvinylsilane;

diethylaminoethyl methacryl-ate;

diethyleneglycol monovinyl ether;

diethyl fumarate;

diethylvinylphosphonate;

l,l-dihydroperfluorobutyl acrylate;

N-( l, l-dihydroperfiuorobutyl -N-ethyl acrylamide;

dimethallyl oxalate;

2,4-dimethoXy-6- fi-itaconylhydrazino) -s-triazine;

2- N, N- dimethyl amino -4-vinyl pyrimidine;

2,3-dimethyl-1,3-butadiene;

dimethyl 'dithiolfumarate;

dimethyl fumarate;

dimethyl methacrylyliminodiacetate;

dinonyl fumarate;

m-divinyl-benzene;

divinyl sulfide;

1,4-diviny1-2,3,5,6-tetrachlorobenzene;

ethyl a-acetoxyacrylate;

ethyl acid fumarate;

ethyl acid maleate;

ethyleneglycol dimethacrylate;

ethyl ,G-ethoxyacrylate;

ethyl methacrylylaminoacetate;

ethyl vinyl ether;

5-ethyl-2-vinylpyridine;

ethyl vinyl sulfide;

N-ethyl-N'-vinylurea;

fumaronitrile;

fumaryl chloride;

glycidyl methacrylate;

hydronopyl acrylate;

p-iodostyrene;

isobutyl vinyl ether;

isopropyl vinyl ether;

maleonitrile;

methacrolein;

4-methacryloXybenzylideneaniline;

4-methacryloxybenzylidene-4'-chloroaniline;

methacryloxymethylpentamethyldisiloxane;

N-methacryloyl-e-caprolactam;

methallyl acetate;

methallyl chloride;

p-methoxystyrene;

methyl acid maleate;

methyl a-chloroacrylate;

methyl thiolacrylate;

methyl vinyl ketone;

Z-methyl-S-vinylpyridine;

methyl vinyl sulfide;

methyl vinyl sulfone;

methyl vinyl sulfoxide;

N-methyl-N-vinyl-p-toluenesulfonamide;

pentachlorophenyl vinyl sulfide;

phenyl vinyl sulfide;

phenyl vinyl sulfone;

poly( 1,3-butyleneglycol fumarate);

poly(ethyleneglycol fumarate);

p-potassium styrenesulfonate;

n-propyl crotonate;

sodium acrylate;

sodium methacrylate;

sodium styrenesulfonate;

sodium vinylsulfonate;

triethoxyvinylsilane;

triethyl aconitate;

N,N,N-triethyl-N-(Z-methacryloxyethyl)-ammonium iodide;

trimethoxyvinylsilane;

trimethyl aconitate;

trimethylsiloxyvinyldimethylsilane;

trimethylvinylsilane;

triisopropoxyvinylsilane;

7 tris(trimethylsiloxyl)vinylsilane; vinyl acetylene; vinyl benzoate;vinyl butyrate; vinyl caprate; vinyl caproate; vinyl isocaproate; vinylcaprylate; 9-vinylcarbazole; vinyl chloroacetate; vinylcyclohexene;vinyl dichloroacetate; vinylene carbonate; vinyl Z-ethylhexanoate; vinylformate; vinyl isocyanate; vinyl isothiocyanate; vinyl laurate; vinyllevulinate; 2-vinylmercaptobenzothiazole; l-vinyln-aphthalene;2-vinylnaphthalene; N-vinyl-Z-oxazolidinone; vinyl palmitate; vinylpelargonate', vinyl perfluorobutyrate; 2-vinylphenanthrene;3-vinylphenanthrene; m-vinylphenol; vinyl pinonate; 2-vinylpyridine;4-vinylpyridine; 4-vinylpyrimidine; N-vinylpyr-rolidone;Z-vinylquinoline; vinyl; vinyl stearate; N-vinylsuccinimide;vinylsulfonic acid; vinyl thiolacetate; 2-vinylthiophene; vinyltrifluoroacetate; vinyl undecylenate; N-vinylurethane; and the like.

The treatment of keratin fibers in accordance with this invention may beconducted at any desired temperature, although temperatures betweenabout 40 and about 60 C. are generally preferred. A temperature in eX-cess of about 100 C. is generally not preferred when a redox catalystsystem is used since some of the components of these systems degrade atelevated temperatures.

In general, such conditions as concentrations of the reagents, pH timeand temperature of reaction may be modified to suit the individualcircumstances and equip ment selected, while still providing the desiredconversion at low homopolymer levels.

Reaction between the keratin fibers and the ethylenically unsaturatedcompounds most readily takes place in the presence of water. Thisgenerally presents no problem since the catalyst components or monomerare preferably applied to the substrate in an aqueous medium. If thesubstrate is dry, however, during exposure to the monomer or lowpolymer, the ensuing reaction will be slower. Consequently, it ispreferred that the substrate fibers be moistened with water when thereaction takes place. Ionic or non-ionic surface active agents may beutilized in any aqueous medium used in applying any of the reagents.

Improved results may be obtained when the keratin fiber substrate is ina swollen condition during reaction. This condition is most readilyobtained by conducting the reaction in the presence of a-swelling agentfor keratin fibers, such as urea, thiourea, lithium salts, such as thechloride, bromide and iodide; guanidine compounds, such 8 as thehydrochlorides; amides, such as formamide, N,N'- dimethylformamide,acetamide, N,N'-dimethylacetamide and the like.

The wool fibers are exposed to the monomer in a most highly preferredembodiment of this invention as a solution in that package dye machineryis readily available and particularly adaptable to the application ofsuch systems to wool fibers. Other liquid systems, such as dispersionsand emulsion, however, may be utilized if desired.

In the preferred embodiment of this invention, the readily polymerizableethylenically unsaturated com pounds are applied to keratin fibers in asubstantially free form, such as in the form of top, tow, roving, sliveror the like. In these forms, the fibers are freer to uncrimp duringtreatment than are the fibers of yarn or fabric. This is. generally trueeven though the fibers are wound quite tightly into package form duringtreatment, although the difference in uncrimping freedom is less Underthis condition. Substantial improvement is obtained, however, even whensuch compounds are applied to yarns and fabrics under the required flowconditions.

Cellulosic fibers, such as cotton, cellulose acetate, viscose rayon andthe like also may be treated in accordance with this invention. Whentreating a cotton substrate, it is generally preferred to conduct thereaction on yarn or fabric. In addition to the above initiating systems,ceric ions also may be used, e.g., in the form of ceric salts, such asceric nitrate, ceric sulfate, ceric ammonium nitrate, ceric ammoniumsulfate, ceric ammonium pyrophosphate, ceric iodate and the like.

A typical apparatus for conducting the processes of this invention isshown in the drawing. The conventional package dye machine shown thereinis a closed system comprising the dye chamber 1, recirculating conduits2, 3 and 15 and pump 4. Feed lines 5, 6, and 7 are used to feed thedesired reagents into the recirculating system. The dye chamber 1 ispartially surrounded by a jacket 8 into which may be fed either steamfor heating or water for cooling. Located within the dye chamber incirculating relationship with conduit 3 is a perforated spindle 9.

The fiber package 10, composed of wool top supported on a cage-likebobbin 11, is mounted on perforated spindle 9. A 4-way reverse valve 12is provided Within the recirculation system for changing the directionof flow of the system or systems utilized, valves 13 and 14 beingprovided for flow rate control.

In operation, an aqueous solution containing the desired ethylenicallyunsaturated compounds and the catalyst components is added through feedline 5 into recirculating conduit 15. This system is then pumped pastthe reverse valve 12 (shown here in outside-in position) into the dyechamber 1, where it is forced nnidirectionally through the fiber packagefrom the outside thereof into the spindles and conduit 3, and thenrecirculated. The reverse valve 12 is periodically switched to theposition shown by dotted lines at 12' in order to reverse the flow offluid from the inside of the spindle to the outside of the package,again unidirectionally. This procedure is repeated until the monomer issubstantially exhausted onto and into the Wool fibers.

Besides package dyeing machinery, other fluid flow machinery adjusted toprovide the desired flow, can be utilized. For example, thepressure-beam dyeing equipment of Burlington Engineering Sales Companyand Gaston County Dyeing Machine Company may be modified for operationin accordance with this invention.

In the following examples, except where noted, each wool sample treatedis scoured by immersing in or having passed therethrough in the packagedye machine, an aqueous solution containing 0.5% on the weight of woolof surfonic N-95, anon-ionic surface active agent and 1.5% onthe weightof wool of glacial acetic acid. After scouring for 20 minutes at 140 F.the sample is rinsed in water at F. for 10-15 minutes. Deionized wateris used in preparing all aqueous media.

9. Example 1 Into a two-pound Gaston County package dye machine, aremounted 800 grams of wool top, 400 grams being mounted on each of twobobbins which are placed on the single perforated spindle of the dyemachine. After scouring and rinsing the wool top, an aqueous solutionmade up from 7400 cc. of H containing 1.74 gms. Fe(No -9H O (0.03% Fe+++based on wool wt.), 12.2 cc. of a 50% solution of H 0 (50/1 molar ratioof peroxide based onFe+++) and 40 cc. of concentrated H SO is circulatedthrough the machine and wool top. After 10 minutes, 960 gms. ofacrylonitrile (enough for 120% pickup) is added into the recirculatingcatalyst system. The resulting system has a pH of 1.3 and provides aliquor/Wool ratio of 11/1. This system is then held at 7585 F. andforced back and forth through the fibers at a flow rate of about 34gallons per minute for 15 minutes at a cycle of 3 minutes outside/in and2 minutes inside/out, after which the temperature is increased to 120 F.by passing steam through the heat jacket of the package dye machine. Thereaction is continued at this temperature for an additional 105 minutes.

The wool top is then removed from the machine and found to haveincreased in weight uniformly by 95.5%.

When this same process is conducted with constant stirring in aone-liter flask, the wool top increases in weight by only 10%. Amongother things, this shows that processes considered inoperable in a flaskare rendered operable by conducting the process in a package dye machineadjusted to deliver the above flow conditions.

A plain weave fabric is produced from the above fibers and compared witha similar fabric reacted as such with the same acrylonit rile system toabout 95% pickup. This latter fabric has lost all fabricproperties,being boardy and coarse in handle, while the fabric produced from theabove wool top is far superior in handle.

The fibers treated in the package dye machine have an uncrimpingextension of 0.79%, an uncrimping energy of 0.0003 gm. cm./cm. grex,tenacity at extension of 0.64 gm./grex, tenacity at the break of 0.85gm./grex and an extension to break of 35.52%, s

.' Example IIv The procedure of Example I is repeated, except that thedischarge pressure is adjusted to various levels and the acrylonitrileis added to the recirculating catalyst system prior to impregnation ofthe fibers therewith. At a discharge pressure corresponding to a flowrate at the dis charge side'of the pump of 10 gallons per minute fromthe package dyeing machine into the recirculating system, the wool topso. treated increases in weight by 94% but contains a large'amount'(from1020% across the wool top) of extractible homopolymer. At this dischargepressure and the various concentrations involved, it is computed thatthe wool is initially contacted by 5.2 lbs. of acrylonitrile/lb. ofwool/minute.

The flow rate is then adjusted to 34 gallons/minute and the wool top sotreated is found to increase in weight by 93%. Atthis increased level offlow, however, little or no homopolymer is deposited upon the wool top.The concentration of acrylonitrile which initially contacts the wool atthis flow rate is calculated to be 17.7 lbs. acrylonitrile/ lb. ofwool/minute.

Even though the wool top samples contain essentially the same amount ofreacted acrylonitrile, the handle of the sample differs radically. Thewool top which was treated at a discharge pressure of 10 gallons/minutefeels harsher than the sample treated at the increased flow rate. Inaddition, the latter wool top is readily processable into yarn, whilethe Wool top treated at the lower flow rate fails to process into yarnbecause of tackiness caused by the large amounts of homopolymer present.

Example 111 Onto the beam of a 100-lb. capacity Gaston County packagedye machine, are wound 63 lbs. of wool top.

The beam is then mounted over the perforated spindle, the machine isclosed and the wool is scoured for 30 minutes at 140 F. with gallons ofwater containing 149 gms. of synfac 905, a non-ionic wetting agentcontaining a nonylphenol-ethylene oxide (1 to 9 to 1 to 2 molar ratio)condensation product, and 429 gms. of acetic acid. During the scouringoperation, as in all succeeding operations in this example, the liquidsare forced back and forth through the wool at a cycle of 4 minutesoutside-to-inside, 6 minutes inside-to-outside.

After scouring, a redox catalyst system maintained at F. and composed of63 gms. of Fe(NO and 429 gms. of 50% H 0 in.75 gallons of water,adjusted to a pH of 1.35 with 12 lbs. of H 80 is passed through the woolfor 20 minutes. The flow rate of the system through the wool is measuredas'about gallons/minute.

Four-teen lbs. of butyl acrylate and 5 lbs. of styrene are then added tothe recirculating catalyst solution and the resulting system is run for20 minutes at 120 F. The remaining monomers (43 lbs. butyl acrylate, 14lbs. styrene) are added to the system continuously until expended-about1% hours. The reaction is continued for an additional 3 hours, afterwhich the machine is drained and the wool is washed with water at 75 F.for 20 minutes' As afinishing operation, the wool is then impregnatedwith 80 gallons of water containing 4% arquad 1650,hexadecyltrimethylammonium chloride lubricant, and 1% synfac 905 for 30minutes at F.

The wool top treated in this manner is found to have increased in weightby 100.6%.

Example IV (Run 33) Example V A package wound from one pound of 1/34syarn is mounted onto the spindle of a package dye machine as used inExample I. The package is scoured at F. by circulating therethrough 10liters of tap water containing 0.5% by weight of surfonic N-95. Themachine is then drained and 10 liters of a 0.2% ferrous ammonium sulfatesolution containing 10 milliliters of 1 N H SO is placed in the machineand circulated for 2 hours, during which time the temperature rises to104? F.

After draining the machine and rinsing the yarn, a solution made up of500 milliliters acrylic acid, 28 milliliters l N H SO and 12 millilitersof 35% hydrogen peroxide in 10 liters of water containing 0.02%methylethyl hydroquinine is introduced into the machine. This solutionis circulated through the yarn package at F. for four hours.

After completion of the reaction, the machine is drained and the packagerinsed with water, then again with a 10 liter solution containing 0.5%surfonic N95 and 10 milliliters hydrochloric acid. After Washing withthis solution for 30 minutes at 140 F., the package is rinsed and dried.Upon weighing, the yarn is found to have increased in weight by anaverage of 35 This yarn is then dyed, along with an untreated controlyarn, in 10 liters of water containing 0.188 gm. sulphon acid blue, 7.5gms. sodium sulfate, 1.5 gms. surfonic N-95 and 2.25 milliliters aceticacid. After boiling in this dye formulation for one hour, the yarn whichhas been reacted with acrylic acid is found to have picked upsubstantially less dye than the untreated control, so

that a fabric produced from both yarns could be dyed to a two-toneeffect with a single dyestuff.

Example VI The procedure of Example III is repeated, except that amonomer system composed of 37.8 lbs. of Z-ethylhexyl acrylate, 37.8 lbs.of styrene and 15 lbs. of dibutyl maleate is used. In three separatetests, the flow rate of the system through the beam of fibers isadjusted to 40 gallons per minute, 80 gallons per minute and 120 gallonsper minute, respectively.

After drying, the three fiber samples are measured for percent pickup,uniformity of pickup from inside to outside of the beam and percentextractible material. Since the same amount of monomers is used in eachtest, the pickup of polymeric material on the fibers is essentially thesame in each test.

The outstanding difference between the three samples is the uniformityof pickup across the beam of reacted wool top. At a flow rate of 40gallons per minute, there is an average variation in'pickup across thebeam of 41% (from 108% in some areas to 67% in others), while at a flowrate of 80 gallons per minute the average variation is even greater at51% (from 121.5% to 70.5%). At a flow rate of 120 gallons per minute,however, the variation is only 14.5% (from 73% to 57.5%), a remarkableimprovement in uniformity of the product.

In extraction tests, wherein the fibers are basted in dirnethylformamidefor 6 hours, less material is removed from the'fibers treated at 120gallons per minute than from those produced at the lower flow rates.

A plain weave fabric produced from yarns made up from the fibers treatedat 120 gallons per minute has a soft, pleasant hand, whereas a similarfabric treated to about 60% pickup by immersion first in the Fe(NO thenin the peroxide and monomer system of this example, has a tacky handlefar inferior to the above fabric produced from reacted wool top.

Example VII Cotton fabric (162.6 g.) is wound on the spool of a /2 lb.package dyeing machine with a flow rate of 6.5 liters/min. Afterscouring and rinsing the cotton as in Example I an emulsion of methylacrylate (180 g.) and Arquad 18 (15 g.) in water (1300 ml.) is added andcirculated while flushing With nitrogen at a temperature of 77 F. Asolution of 0.1 M ceric ammonium nitrate/ N-nitric acid (50 ml.) is thenadded dropwise over 75 min. with circulation at 77 F., and the liquidthen discarded.

The resultant product is then rinsed with water, neutralized with a 1%solution of sodium bicarbonate and rinsed again to a final pH of 6.After air-drying, the treated sample is found to weigh 295 g., theweight increase being 82%.

It has been shown above that fabrics of improved handle can be providedby treating fibers in generally lose form and processing them intofabrics. This process can be greatly improved by conducting the processunder certain conditions of forced flow. The small amounts, or absence,of homopolymer when these processes are conducted under certainconditions of flow eliminates the necessity for conducting extractiontechniques,

In addition, the forced'flow process provides a technique whereby theamount of homopolymer formed may be controlled, from the point ofelimination to controlled low levels. In addition, less time is requiredto get efficient conversion of available monomer. Furthermore, theproducts prepared in accordance with this invention are much whiter thanfibers of prior art processes, which often are substantially darkenedduring treatment. This greatly increases the uses of such fibers inproviding fibers suitable for use in fabrics dyed to light pastelshades.

()ne of the outstanding advantages of the forced flow rate systemprovided by this invention is that wool fibers may be treated with asingle system containing both the catalyst Components and the monomerwithout forming appreciable amounts of homopolymer.

That which is claimed is:

1. A process for modifying the characteristics of continuous lengths ofloose, non-woven textile fibers which are confined in a givenconfiguration throughout the modification comprising providing asolution of a compound containing the group and a fibrous substrate;forcing said solution at a rate substantially greater than that possibleas a result of merely refluxing said fibers in said solution throughsaid fibrous substrate unidirectionally, intermittently back and forththroughout the process, said process being conducted in the presence ofa chemical catalyst for the polymerization of said compound.

2. The process of claim 1 'wherein keratin fibers are treated, saidfibers being in a condition whereby they are substantially free touncrimp from their natural crimp level while said solution is beingforced therethrough.

3. The process of claim 1 wherein the solution is forced at asufliciently rapid rate that the supply of compound at the surface ofthe fibers is constantly being replenished in an amount, at leastinitially, considerably in excess of that which the fibers can haveexhausted therein.

4. The process of claim 1 wherein the compound is supplied to the fibersurfaces at a rate in excess of about 5 lbs/lb. of fibers/minute.

5. The process of claim 1 wherein said solution is forced past thefibers at a rate so as to provide an excess of at least about 1000 timesthat which theoreti cally, initially, exhausts per minute.

6. The process of claim 1 wherein the chemical catalyst comprises aredox catalyst system.

References Cited by the Examiner Lipson et al.: Nature, vol. 157, p. 590(1946).

Lipson et al.: Nature, vol. 157, p. 736 (1946).

Lipson: Nature, vol. 164, p. 576 (1949).

Speakman et al.: Journal of the Society of Dyers and Colorists, vol. 70,pp. 112-116 (1954).

Valentine: Journal of the Textile Institute, T27 0-T283,

1. A PROCESS FOR MODIFYING THE CHARACTERISTICS OF CONTINUOUS LENGTHS OF LOOSE, NON-WOVEN TEXTILE FIBERS WHICH ARE CONFIRMED IN A GIVEN CONFIGURATION THROUGHOUT THE MODIFICATION COMPRISING PROVIDING A SOLUTION OF A COMPOUND CONTAINING THE GROUP CH2=C< AND A FIBROUS SUBSTRATE; FORCING SAID SOLUTION AT A RATE SUBSTANTIALLY GREATER THAN THAT POSSIBLE AS A RESULT OF MERELY REFFLUXING SAID FIBERS IN SAID SOLUTION THROUGH SAID FIBROUS SUBSTRATE UNIDIRECTIONALLY, INTERMITTENTLY BACK AND FORTH THROUGHOUT THE PROCESS, SAID PROCESS BEING CONDUCTED IN THE PRESENCE OF A CHEMICAL CATALYST FOR THE POOLYMERIZATION OF SAID COMPOUND. 